The Cthulhu Hack by Just Crunch Games
Rules light, courtesy of its use of the Black Hack engine, rules for Cthulhu investigative horror. It’s just been upgraded to version 1.5, which refines this already sharp ruleset. Oh and its supplements are also in the sale.

Mythras by Design Mechanism
If you’ve not got this behemoth of D100 goodness by now here’s your chance. As well as the core system, which is a complete thing and good to go running a wide variety of fantasy settings of various genres, all the formidable selection of adventures and setting books are in the sale.

My recommendations: Mythic Rome & Mythic Britain (including Mythic Britain: Logres, the supplement by D101 collaborator Paul Mitchener about the Anglo Saxons), and I’m going to use the sale to catch up with the Monthly Mythras adventures that I’ve woefully fallen behind on.

Clockwork and Chivalry by Cakebread and Walton
The English Civil War as fought by Alchemical Cavaliers and Clockwork device using Roundheads. One of my favourite settings of all time, and the D100 Renaissance system (an offspring of OpenQuest) makes me grin even more. Also check out the epic Pirates & Dragons, if you fancy a bit of fantasy Pirates in the vein of Pirates of the Carribean.